The Hubble telescope just discovered a relic that changes the way we understand our galaxy

A dense cloud of stars in the middle of the Milky Way could
reveal a lot about our galaxy’s past.

The cluster is called Terzan 5 and Italian researchers have found evidence that
it could be the same as the building blocks that made up our
galaxy, because of the striking similarity of its stars to the
most ancient ones in the Milky Way.

Terzan 5 lies 19,000 light-years away from Earth and there are
two kinds of stars within it, which differ in the elements they
contain and have an age gap of around seven billion years; some
were formed 4.5 billion years ago and others are far older,
forming as long as 12 billion years ago.

According to the team, this group of stars — known as a globular
cluster — is unlike any they have identified before, and have
named it a living fossil from the formation of the Milky
Way.

While other stars dissolved and merged to form our galaxy, Terzan
5 managed to survive and so still exists as a relic of this
early process.

"We think that some remnants of these gaseous clumps could remain
relatively undisrupted and keep existing embedded within the
galaxy," said Francesco Ferraro, lead author of the study from
the University of Bologna. "Such galactic fossils allow
astronomers to reconstruct an important piece of the history of
our Milky Way."